Magnetic tunnel junction with compensation element

Abstract

A magnetic tunnel junction having a compsensation element is disclosed. The magnetic tunnel junction includes a reference element, and a compensation element having an opposite magnetization moment to a magnetization moment of the reference element. A free magnetic layer is between the reference element and the compensation element, and an electrically insulating and non-magnetic tunneling barrier layer separates the free magnetic layer from the reference element. The free magnetic layer includes Co 100-X-Y Fe X B Y wherein X is a value being greater than 30 and Y is a value being greater than 15.

What is claimed is: 
     
       1. A magnetic tunnel junction, comprising:
 a reference element; 
 a compensation element having an opposite magnetization moment to a magnetization moment of the reference element; 
 a free magnetic layer between the reference element and the compensation element, the free magnetic layer having a saturation moment value being greater than 1100 emu/cc; 
 an electrically insulating and non-magnetic tunneling barrier layer separating the free magnetic layer from the reference element; and 
 an electrically insulating layer separating the compensation element from the free magnetic layer. 
 
     
     
       2. A magnetic tunnel junction according to  claim 1 , wherein the free magnetic layer has a saturation moment value greater than 1500 emu/cc. 
     
     
       3. A magnetic tunnel junction according to  claim 1 , wherein the electrically insulating layer has a thickness in a range from 3 to 15 Angstroms. 
     
     
       4. A magnetic tunnel junction according to  claim 1 , wherein the electrically insulating layer is an electrically insulating and electronically reflective layer. 
     
     
       5. A magnetic tunnel junction according to  claim 4 , wherein the free magnetic layer comprises Co 100-x-y Fe x B y  wherein X is a value being greater than 30 and Y is a value being greater than 15. 
     
     
       6. A magnetic tunnel junction according to  claim 3 , further comprising an electrically conductive and non-ferromagnetic spacer layer disposed between the compensation element and the electrically insulating layer. 
     
     
       7. A magnetic tunnel junction according to  claim 6 , wherein the compensation element is a synthetic antiferromagnetic element comprising a Ru, Pd or Cr spacer layer and the non-ferromagnetic spacer layer comprises Ta, Cu, Al, Mg, or Au. 
     
     
       8. A magnetic tunnel junction according to  claim 4 , wherein the electrically insulating and electronically reflective layer comprises TaO, AlO, MgO, SiO, TiO, NiO, TaN, or AlN and has an area resistance value in a range from 1 to 50 ohmμm 2 . 
     
     
       9. A magnetic tunnel junction according to  claim 1 , wherein the reference element has a spin polarization of more than 0.5. 
     
     
       10. A magnetic tunnel junction according to  claim 1 , wherein the compensation element has a spin polarization in a range from 0.2 to 0.9. 
     
     
       11. A magnetic tunnel junction, comprising:
 a reference element; 
 a compensation element; 
 a free magnetic layer between the reference element and the compensation element, the free magnetic layer having a saturation moment value being greater than 1100 emu/cc; 
 an electrically insulating and non-magnetic tunneling barrier layer separating the free magnetic layer from the reference element; and 
 an electrically insulating and electronically reflective layer having a thickness in a range from 3 to 15 Angstroms and being between the compensation element from the free magnetic layer. 
 
     
     
       12. A magnetic tunnel junction according to  claim 11 , wherein the electrically insulating and electronically reflective layer comprises TaO, AlO, MgO, SiO, TiO, NiO, TaN, or AlN and has an area resistance value in a range from 1 to 50 ohmμm 2 . 
     
     
       13. A magnetic tunnel junction according to  claim 11 , further comprising an electrically conductive and non-ferromagnetic spacer layer disposed between the compensation element and the electrically insulating and electronically reflective layer. 
     
     
       14. A magnetic tunnel junction according to  claim 13 , wherein the compensation element is a synthetic antiferromagnetic element comprising a Ru, Pd or Cr spacer layer and the non-ferromagnetic spacer layer comprises Ta, Cu, Al, Mg, or Au. 
     
     
       15. A magnetic tunnel junction according to  claim 13 , wherein the free magnetic layer comprises Co 100-x-y Fe x B y  wherein X is a value being greater than 30 and Y is a value being greater than 15. 
     
     
       16. A magnetic tunnel junction according to  claim 11 , wherein the free magnetic layer has a saturation moment value greater than 1500 emu/cc. 
     
     
       17. A magnetic tunnel junction according to  claim 11 , wherein the reference element has a spin polarization of more than 0.5. 
     
     
       18. A magnetic tunnel junction according to  claim 11 , wherein the compensation element has a spin polarization in a range from 0.2 to 0.9. 
     
     
       19. A spin-transfer torque memory cell, comprising:
 a reference element; 
 a compensation element having an opposite magnetization moment to a magnetization moment of the reference element; 
 a free magnetic layer between the reference element and the compensation element, the free magnetic layer having a saturation moment value being greater than 1100 emu/cc; 
 an electrically insulating and non-magnetic tunneling barrier layer separating the free magnetic layer from the reference element; 
 an electrically insulating and electronically reflective layer having a thickness in a range from 3 to 15 Angstroms and being between the compensation element from the free magnetic layer; and 
 an electrically conductive and non-ferromagnetic spacer layer disposed between the compensation element and the electrically insulating and electronically reflective layer. 
 
     
     
       20. A magnetic tunnel junction according to  claim 19 , wherein the free magnetic element has a saturation moment value greater than 1500 emu/cc.